Re: [PATCH v5 5/8] powerpc/watchpoint: Fix exception handling for CONFIG_HAVE_HW_BREAKPOINT=N

[Ravi Bangoria <ravi.bangoria@linux.ibm.com>]

Hi Christophe,

>> diff --git a/arch/powerpc/kernel/ptrace/ptrace-noadv.c b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
>> index 57a0ab822334..866597b407bc 100644
>> --- a/arch/powerpc/kernel/ptrace/ptrace-noadv.c
>> +++ b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
>> @@ -286,11 +286,16 @@ long ppc_del_hwdebug(struct task_struct *child, long data)
>>       }
>>       return ret;
>>   #else /* CONFIG_HAVE_HW_BREAKPOINT */
>> +    if (child->thread.hw_brk[data - 1].flags & HW_BRK_FLAG_DISABLED)
> 
> I think child->thread.hw_brk[data - 1].flags & HW_BRK_FLAG_DISABLED should go around additionnal ()

Not sure I follow.

> 
>> +        goto del;
>> +
>>       if (child->thread.hw_brk[data - 1].address == 0)
>>           return -ENOENT;
> 
> What about replacing the above if by:
>      if (!(child->thread.hw_brk[data - 1].flags) & HW_BRK_FLAG_DISABLED) &&
>          child->thread.hw_brk[data - 1].address == 0)
>          return -ENOENT;
okay.. that's more compact.

But more importantly, what I wanted to know is whether CONFIG_HAVE_HW_BREAKPOINT
is set or not in production/distro builds for 8xx. Because I see it's not set in
8xx defconfigs.

Thanks,
Ravi